What Does Mold Saving In The Mold Mean?

Mold saving refers to the fitting that does not reach the design accuracy when assembling the mold, and abnormalities will occur when the product is produced, and the required accuracy is not reached, and the mold saving process is required for fine adjustment.

The method of mold saving generally needs to be carried out in accordance with the standard operating steps. The operator of the mold optical polishing plant needs to strictly follow the following mold-saving operation methods to do the most basic mold-saving polishing for the mold.

1. When a new mold starts to be processed, it should be cleaned with firewater (kerosene) first, and then all oil stains and unnecessary objects should be wiped off with alcohol so that when the mold is filled with an oilstone, the oilstone surface will not stick to dirt and the cutting function is lost.
2. When saving molds, the bottom corners, bone pits, and dead corners of the mold should be saved first, and the protrusions and large planes should be saved later.
3. Some of the modules are embedded in three to four pieces to form a module. Only rough or fire patterns are punched along the edges of the individual die openings, and then all the modules are clamped to be smooth, and the plastic parts are clamped when they are out. The position will be slightly smoother.
4. For modules with large planes or high protrusions, be sure to use flat steel sheets and the red lead to check whether the modules are uneven or reversed after the rough grains are removed. If there is any unevenness in the finished product, it will stick mold or drag flowers.
5. If the module is a flat surface and maybe a sealing position in a certain place, we can use double-sided adhesive tape to paste sandpaper on the edges that do not want to save the mold, so as to ensure that there is no place that should not be saved.
6. Use copper or bamboo to press the sandpaper to save the mold. Keep in mind that the sandpaper should not be larger than the area of the tool or even the place that should not be hit by the extra sandpaper to round the mouth or change the status of unevenness.
7. For processing with copper or bamboo, the shape of the tool should be similar to that of the mold, so as not to save the mold. For example, flat bamboo should be used for the plane, and small or round bamboo should be used for processing the small or round surface.
8. When the mold-saving plane is next to the protruding position, sandpaper or oil stone should be struck at 15 to 30 degrees syncline to avoid a deep hole next to the protruding position.
9. For example, when the crude oil stone is 150#, 180#, 220#, and other oil stones, fire water should not be added, except for light 320# and above. Manual use of copper or bamboo pieces depends on the environment at the time.
10. If the module is not allowed to have fire patterns, the saver must see them clearly or use different methods to find the fire patterns and remove them. Because there are patterns after each trial of the mold. The module must be assembled and disassembled and tried again mold, it will cost a lot of man-hours and waste materials.
11. Check the fire pattern method of the module. After the module is cleaned, the surface of the copper acid can be evenly coated with a brush. After about 3 to 5 minutes, the module is washed with water and dried with an air gun. After the test, the molds with no fire patterns on the surface will be darkened, and those with fire patterns on the surface will show shiny spots. Repeat the treatment with oilstone or sandpaper until there is no fire pattern, and it will be completely darkened after the copper acid test.
12. You don’t need to be more serious about the blister copper male than the young copper male. As long as you omit the protruding parts of the copper male surface or the convex position, you don’t have to save the concave part. We need to find the problem to save the mold.
13. If the copper male is placed on the bronze fixture of the spark machine, the four benchmark nails below must be placed on the bottom with a soft object (such as cloth, paper) to avoid unnecessary damage when the workpiece is moved, and put it on the table or on the shelf.
14. Use hand or machine to hit above 400# sandpaper. Pay attention to the clean environment around the module. The sandpaper should be rubbed on the sandpaper rolls before cutting, and the slightly coarse sand particles on the sandpaper should be removed. This will reduce the sudden roughness when polishing.
15. If the model saver finds an abnormality, he should report it to the supervisor. The manager should be notified when the model is completed, and should not be handed over without completion.

Advantages And Disadvantages Of Two-Shot Injection Molding

There are a variety of manufacturing methods used to create products using plastic polymers, including Two Shot Mold, compression thermoset molding, and extrusion. Although all of these are viable manufacturing processes, this process has several advantages that make it the first choice of many plastic manufacturers. The process is relatively simple; one material is injected into the mold to make the initial part of the product, and then the second injection of the second material is compatible with the original material. Many manufacturers use this method to make plastics or polymers for three good reasons.

Two-shot injection molding is cost-effective

The two-step process only requires one machine cycle to rotate the initial mold and place the second mold around the product so that the second compatible thermoplastic can be inserted into the second mold. Since the technology uses only one cycle, rather than a separate machine cycle, any production run with a lower cost requires fewer employees to produce the final product, and each run provides more items. It also ensures a firm bond between materials without the need for further assembly lines.

Strengthen product quality

Two-shot injection molding can improve the quality of most thermoplastic products from the following aspects:

Improved aesthetics. Items made of different colored plastics or polymers look better and are more attractive to consumers. If the product uses more than one color or texture, it will appear more expensive.

Improve ergonomics. Because this process allows the use of a soft-touch surface, the resulting project can have ergonomically designed handles or other parts. This is especially important for tools, medical equipment, and other hand-held items.

When silicone and other rubber materials are used for gaskets and other parts that require a strong seal, it provides a better seal.

It allows you to combine the superior comfort and practicality of hard and soft polymers, even for the smallest products.

Compared to overmolding or more traditional insertion processes, it can greatly reduce the number of misalignments.

It enables manufacturers to create more complex mold designs using multiple materials that cannot be effectively bonded by other processes.

This bond is very strong, creating a product that is more durable, more reliable and has a longer lifespan.

Versatility

Product manufacturers favor a wide range of applications for two-shot injection molding, including automotive interior parts, medical equipment, tools, and toys. It allows manufacturers to combine various materials and colors to create a strong and attractive final product. Some materials can be effectively combined with this process, including silicone and thermoplastics, nylon and thermoplastic elastomers, or hard nylon and soft-touch materials.

Two-shot injection molding can solve your company’s product production difficulties. An experienced plastic manufacturer can guide you from concept to finished product and ensure a cost-effective solution.

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The Difference Between Double Shot Molding And Overmolding

 There are a variety of manufacturing methods used to make plastic molded products. The two methods mentioned in this article, double shot molding, and over-molding, are viable manufacturing processes and provide some advantages for many plastic manufacturers. Both of these processes are difficult to master because they require very strict tolerances. Below, we discuss the differences and advantages of double-shot molding and over-molding.

Two-shot molding

Two-shot molding, sometimes called double-shot molding, is a manufacturing process that uses two different materials to produce complex molded parts by molding plastic around preformed metal or plastic inserts. The process is relatively simple; one material is injected into the mold to make the initial part of the product, followed by a second injection of another material that is compatible with the initial injection molded part. The two plastic resins then form molecular bonds, and the multi-resin molding is cooled and ejected.

Two Shot Mold is an ideal process for complex, multi-material, multi-color plastic products; especially in mass production scenarios. Other advantages include:

Lower unit cost.

Reduce costs and waste associated with assembly defects.

improve product quality.

Overmolding

Overmolding is the process of adding an extra layer of material to an existing piece or component. This process is usually used for manufacturing parts, sub-parts of parts, and prototype development. Typically, the substrate material (the first piece of other material that will be bonded and mechanically interlocked) is placed in an injection molding tool, at which point the mold material is shot into or around the substrate. When the over-mold material solidifies, the two materials are combined as a single part.

If you over-molding a metal part with plastic, you can really use any type of plastic. If you are over molding a plastic part with another plastic, there may be some compatibility issues. Your experienced molder will be able to recommend the best material for your project.

By adding textures, colors, and adding necessary functional components, over-molding can be added to change the surface of a piece or product. Other advantages include:

Enhance design flexibility and multi-material components.

Reduce secondary operations; assembly and labor costs.

Improve the strength and structure of parts.

As mentioned above, these processes are relatively easy to understand. However, it is very difficult to master. It requires a high level of technical expertise and attention to detail. When dealing with high-volume production scenarios, the smallest errors can also bring huge losses. This is why it is important to find a high-capacity molding manufacturer. Once you find one, you need to involve them early in the design phase of your part, because they can design value and quality into any problem area.

Two-Shot Molding vs. Overmolding

 Injection molding is a popular manufacturing process, which can quickly produce complex-shaped precise parts without wasting a lot of materials.

Many different processes belong to the category of injection molding, including over-molding and two-shot molding. The two processes are similar, but there are some key differences-here are what engineers and designers need to know:

What is two-shot molding?

Two Shot Injection Molds, also known as dual-molds, double-shot molds, or multi-shot molds, are a subcategory of injection molding that allows engineers to create multi-material or multi-colored parts without adding additional assembly steps.

Through the different layers of materials or colors created by the injection molding machine, the two-shot injection molding process is best understood. The first material is injected into the mold to create the substrate, and other materials or materials will be molded around the substrate. After the substrate solidifies and cools, it is transferred by hand, robotic arm, or rotating plane to another cavity of the mold.

From there, the mold opens and rotates 180° with one side of the substrate to meet the other mold chamber and injection molding nozzle. Once the substrate is in place, the second material is injected and combined with the substrate to form a firm hold. Once the second layer has cooled, the last part will be sprayed out.

Engineers should know that Two Shot Mold can be accelerated or slowed down, depending on how the substrate is transferred to another cavity of the mold. Hand and robot arm transfer takes longer than the rotating plane, but the rotating platen molding is more expensive, usually, there are only high-efficiency options, mass production runs.

In addition, it is very important that the material of the mold is easy to bond, and the mold must be aligned to prevent deformation of the parts.

Advantages and disadvantages of two-shot molding

Two-shot injection molding is efficient and economical manufacturing technology. This process also produces highly durable terminal parts and assemblies.

From a design point of view, two-shot molding provides designers with a lot of flexibility, because this process can create complex geometric shapes and adapt to multiple colors to produce more beautiful parts.

In addition, because one machine manufactures the entire part, no post-processing is required, and engineers can greatly reduce manufacturing time, thereby reducing costs. However, it is worth noting that the initial two-shot injection molding machine may be costly, and the two-shot injection molding machine is more expensive than the standard injection molding machine. Fortunately, these costs are usually offset by labor savings and assembly costs for large-scale production runs.

What is over-molding?

Overmolding, like Two Shot Moulding, is a multi-shot injection molding process that produces a single final product from two or more different thermoplastics. This process is ideal for engineers who want to build components that are powerful, functional, beautiful, and that will not separate over time.

At the beginning of the over-molding process, engineers inject the substrate with a harder over-molding material. Then, the substrate is placed in an over-mold tool or an over-mold cavity within the same mold. The molten-over mold material is then sprayed into, onto, or around the substrate. After the molten material is cooled, the substrate and the over-mold are chemically or mechanically combined. The entire over-molding process only takes 30 seconds.

The product team must remember that all thermoplastics used in the over-molding process must be chemically or thermally compatible with each other. Compatibility with metal substrates is usually not a problem, because they can be used with any plastic over mold, but the product team may encounter compatibility issues when using plastic over molds. If the substrate and mold are not compatible, the final product may be deformed or poorly bound.

However, if two less compatible plastics must be used, the team can design mechanical bonding properties for the part after the fact, although this may result in higher costs.

Advantages and disadvantages of over-molding

Overmolding and two-shot injection molding have many of the same advantages. They are ideal for quickly creating durable, reliable, and vibration-resistant parts with complex geometries, but over-molding is best suited for low-volume production runs.

Compared with two-shot molding, over-mold design is also easier, because engineers can use any standard injection molding machine to carry out this process.

In terms of disadvantages, the tolerances of over-molded parts are often lower than those of two-shot injection molding. It is also important to remember that plastic compatibility requirements may constrain designers.